JP2921092B2 - Waterless lithographic plate processing solution - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a processing solution for lithographic plate making without water, and more particularly, to a processing solution for waterless lithographic plate having an excellent processing effect and a long service life. It is.

[Prior Art] Various waterless lithographic printing plates comprising a photosensitive layer and a silicone rubber layer are known. Above all, by subjecting an image forming laminate having a photosensitive layer and a silicone rubber layer having a quinonediazide structure as constituents on a support in this order to an amine treatment, a negative,
As disclosed in JP-A-59-17552, a method for obtaining a water-free lithographic printing plate of a positive amphoteric type is a development latitude including image reproducibility, solvent resistance, developability and the like of a waterless lithographic printing plate. And that the negative and positive plates can be made from the same plate material. The base treatment methods described in these patents use amines alone or as a mixture and are used in a gas phase or in a liquid state. In the case of a liquid state, water or a known organic solvent is used as a solvent.

As described above, amines have been particularly used in the waterless lithographic processing solution according to the prior art, but the amine does not reduce the amine concentration which is considered to be caused by its volatility and carbonate formation with carbon dioxide in the air. There is a problem that the treatment effect is reduced, and there has been a demand for the development of another treatment solution which does not have these disadvantages and is excellent in treatment effect.

[Problems to be Solved by the Invention] The present inventors have conducted intensive studies in order to improve the problems of the related art, and as a result, when a processing solution containing 1,3-dialkyl-2-imidazolidone was used, The present inventors have found that the above problems can be satisfactorily solved while having a treatment effect at a level equal to or higher than the case where an amine is used as described above, and have reached the present invention.

Accordingly, it is an object of the present invention to provide a processing liquid for flat plate making without water, which has excellent processing effects such as image reproducibility, solvent resistance and developability, and has a long processing liquid life without a reduction in processing effects. .

[Means for Solving the Problems] That is, the present invention provides a processing solution for waterless lithographic plate-making in which a photosensitive layer and a silicone rubber layer each having a quinonediazide structure-containing substance as constituents are coated on a support in this order. Wherein the treatment liquid is mainly composed of a solvent and 1,3-dialkyl-2-imidazolidone represented by the following general formula [I].

(Where R ₁ and R ₂ may be the same or different and may be the same or different alkyl groups having 1 to 10 carbon atoms. R ₃ and R ₄ may be a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, and Or a different solvent.) Examples of the solvent used in the treatment liquid of the present invention include:
Water, alcohols (methanol, ethanol, 1-propanol, 2-propanol, 3-methoxybutyl alcohol, 2-methylpentanol-1, ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol,
Dipropylene glycol, tripropylene glycol,
Polypropylene, etc.), esters (ethyl acetate, ethyl cellosolve acetate, methyl cellosolve acetate, carbitol acetate, etc.), ethers (ethylene glycol monomethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, triethylene glycol monomethyl ether) , Triethylene glycol monoethyl ether, triethylene glycol monobutyl ether, polyethylene glycol monomethyl ether, propylene glycol monomethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether,
Examples thereof include dipropylene glycol monomethyl ether, tripropylene glycol monomethyl ether, polypropylene glycol monomethyl ether, and ketones (cyclohexanone, acetonylacetone, diacetone alcohol, and the like), and these are used alone or in combination. Emulsions with appropriate emulsifiers and surfactants can also be used.

The 1,3-dialkyl-2-imidazolidone used in the present invention is represented by the general formula (I).

(Where R ₁ and R ₂ may be the same or different and may be the same or different alkyl groups having 1 to 10 carbon atoms. R ₃ and R ₄ may be a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, and Or a different one.) 1,3-Dialkyl-2 represented by the above general formula (I)
-Imidazolidone has good compatibility with the processing solvent, excellent stability, and low toxicity.

Specific examples of the 1,3-dialkyl-2-imidazolidone that can be used in the present invention include, for example, the following, but are not limited thereto.

1,3-dimethyl-2-imidazolidone, 1,3-diethyl-2-imidazolidone, 1,3-dipropyl-2-imidazolidone, 1,3-dibutyl-2-imidazolidone, 1,3-
Diacryl-2-imidazolidone, 1,3,4-trimethyl-2-imidazoliton, 1,3-dimethyl-4-ethyl-
2-imidazolidone, 1,3,4,5-tetramethyl-2-imidazolidone, 1,3,4,5-tetraethyl-2-imidazolidone.

The treatment liquid of the present invention can be prepared by adding at least one kind of 1,3-dialkyl-2-imidazolidone to the above-mentioned treatment liquid solvent or a mixed solvent thereof.

The amount of 1,3-dialkyl-2-imidazolidone incorporated in the treatment liquid is not particularly limited, but is added in the range of 0.1 to 70% by weight based on the total amount of the treatment liquid from the viewpoint of treatment effect and economy. Preferably, more preferably 0.3 to 45
% By weight.

When used as a treatment liquid, a surfactant may be added to the treatment liquid for improving wettability. When developing directly with a processing solution, dyes such as Neptune Blue Base 627 (manufactured by BASF), Aizen Victoria Blue BH, Aizen Marine RNX (manufactured by Hodogaya Chemical Co., Ltd.), etc. are used to improve plate inspection. Can be added to the processing solution.

Further, aliphatic hydrocarbons (hexane, heptane, gasoline, kerosene, "Isoper" (manufactured by Exxon Chemical Co., Ltd.), etc.) may be added to the treatment liquid.

The support used in the present invention may be any of those used in ordinary waterless lithographic printing plates, or any proposed ones, for example, aluminum, iron, metal plates such as zinc and polyester, polyolefin, Examples include a transparent or opaque plastic film such as polystyrene, or a composite of both. These sheets can be further coated with a resin layer or the like for the purpose of preventing halation or for other purposes, and used as a support.

The photosensitive layer according to the invention is composed of a material containing a known quinonediazide structure, and the material containing a quinonediazide structure is usually used for a positive PS plate, a wipe-on plate, a photoresist, and the like. Quinonediazides.

Such quinonediazides include, for example, esters of benzoquinone-1,2-diazide-4- or -5-sulfonic acid with polyhydroxyphenyl, naphthoquinone-1,
Esters of 2-diazide-4- or -5-sulfonic acid with pyrogallol acetone resin, naphthoquinone-1,2-
Esters of diazide-4- or -5-sulfonic acid with phenol formaldehyde novolak resin or cash-modified novolak resin. In addition, a small amount of a quinonediazide compound (for example, an esterified product of naphthoquinone-1,2-diazide-5-sulfonic acid and phenol, cresol, xylenol, catechol, pyrogallol, bisphenol A, or the like) or a resin containing the above quinonediazide group Novolak resin containing no photosensitive group (for example, a soluble fusible resin obtained by condensing phenols such as phenol, cresol, xylenol, catechol and pyrogallol with formaldehyde in the presence of an acidic catalyst). You may mix.
Further, a photo-peelable photosensitive layer in which quinonediazides are crosslinked with a polyfunctional compound as proposed in JP-A-56-80046 is exemplified.

As the crosslinking agent, polyfunctional isocyanates, for example, paraphenylene diisocyanate, 2,4- or 2,6
-Tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate or an adduct thereof, or a polyfunctional epoxy compound, for example,
Examples include polyethylene glycol diglycidyl ethers, polypropylene glycol diglycidyl ethers, bisphenol A diglycidyl ether, and trimethylolpropane triglycidyl ether. These thermosettings do not lose the photosensitivity of the photosensitive material, usually 130 ° C
Preferably, the reaction is performed in the following manner. For this reason, a catalyst or the like is usually used in combination.

Also, as a method of reacting a quinonediazide with a monofunctional compound to denature it and make it hardly soluble or insoluble in a developer,
Similarly, active groups of the quinonediazides can be esterified, amidated, urethanized, and the like.
The compound to be reacted with an active group of quinonediazides may be a low molecular weight or a relatively high molecular weight,
Monomers may be graft-polymerized to quinonediazides.

Particularly preferred as the photosensitive layer used in the present invention is obtained by crosslinking or modifying a partially esterified product of naphthoquinone-1,2-diazide-5-sulfonic acid and phenol formaldehyde novolak resin with a polyfunctional or monofunctional isocyanate. It is a thing.

The thickness of the photosensitive layer is about 0.1-100 μm, preferably about 0.5-10 μm.
μ is appropriate. If it is too thin, defects such as pinholes are likely to occur during coating, while if it is too thick, it is disadvantageous from an economic viewpoint. Further, other components can be added to the photosensitive layer for the purpose of improving the coating film forming property and the adhesiveness to the support as long as the effects of the present invention are not impaired.

As the silicone rubber layer used in the present invention, a layer mainly composed of a linear organic polysiloxane having a molecular weight of several thousand to several hundred thousand having the following repeating units is preferably used.

Here, n is an integer of 2 or more, and R ₁ and R ₂ are an alkyl group having 1 to 10 carbon atoms, an alkenyl group or a phenyl group,
It is preferable that 60% or more of the total of R ₁ and R ₂ is a methyl group.

A crosslinking agent is usually added to the linear organic polysiloxane. As the cross-linking agent, there are acetoxy silane, ketoxime silane, alkoxy silane, amino silane, amido silane and the like used for so-called room temperature (low temperature) curable silicone rubber, and the terminal is usually a hydroxyl group as a linear organic polysiloxane. In combination with these, it becomes a deacetic acid type, a deoxime type, a dealcohol type, a deamine type, and a deamide type silicone rubber, respectively. A small amount of an organotin compound or the like may be further added to these silicone rubbers as a catalyst.

The thickness of the silicone rubber layer is suitably about 0.5-100 μm, preferably about 0.5-10 μm.If it is too thin, it may cause a problem in terms of printing durability, while if it is too thick, it is economically disadvantageous. In addition, it becomes difficult to remove the silicone rubber layer at the time of development, and the image reproducibility is lowered.

In the printing plate used in the present invention, the adhesion between the support and the photosensitive layer, and between the photosensitive layer and the silicone rubber layer, is very important for basic plate performance such as image reproducibility and printing durability, so it is not necessary. Accordingly, it is possible to provide an adhesive layer between each layer or to add an adhesion improving component to each layer. In particular, for the adhesive force between the photosensitive layer and the silicone rubber layer, it is effective to provide a known silicone primer or silane coupling agent layer between the layers or to add a silicone primer or silane coupling agent to the silicone rubber layer or the photosensitive layer. is there.

A thin protective film can be laminated on the surface of the waterless planographic printing plate precursor configured as described above.

The waterless planographic printing plate precursor used in the present invention is manufactured, for example, as follows. First, on a support, using a normal coater such as a reverse roll coater, an air knife coater, or a Meyer bar coater, or a spin coater such as a wooler, apply a composition to constitute a primer layer, and then dry and coat as necessary. Heat cured to form a primer layer.
On the primer layer, a photosensitive layer composition for forming a photosensitive layer is applied, dried and, if necessary, thermally cured to form a photosensitive layer. After providing an adhesive layer on the photosensitive layer if necessary,
Apply an uncured composition of silicone rubber, usually 50-130
Heat treatment for several minutes at a temperature of ° C. to cure sufficiently to form a silicone rubber layer. If necessary, a protective film is covered on the silicone rubber layer using a laminator or the like.

The thus obtained waterless planographic printing original plate is subjected to image exposure using a positive film or positive original, or a negative film or negative original, and then developed to obtain a waterless planographic printing plate.

The plate making method of such a lithographic printing plate precursor without water includes the following. For example, when used as a positive type waterless lithographic printing original plate, through a vacuum-contacted positive film or positive original, 5 to 60 of quinonediazide units of a substance containing a quinonediazide structure in the photosensitive layer with actinic rays are used.
The image exposure was given so that mole% was photodegraded,
When processing is performed simultaneously with a processing solution containing 3-dialkyl-2-indazolidone and development is performed, a waterless planographic printing plate is obtained.

On the other hand, when used as a negative type waterless lithographic printing original plate, through a negative film or negative original which is vacuum-contacted, normal image exposure with actinic rays (60 mol% of the quinone diazide unit of the substance containing a quinone diazide structure in the photosensitive layer is performed. Image exposure so that the excess amount is photolyzed)
After processing with a processing solution containing a solvent and 1,3-dialkyl-2-indazolidone, developing, or simultaneously developing with a processing solution containing a solvent and 1,3-dialkyl-2-imidazolidone, or developing Later, when treated with a processing solution containing a solvent and 1,3-dialkyl-2-imidazolidone, a waterless planographic printing plate is obtained.

The light source used in this exposure step generates abundant ultraviolet rays, and a mercury lamp, a carbon arc lamp, a xenon lamp, a metal halide lamp, a fluorescent lamp and the like can be used. Further, a laser beam or the like is used in addition to ultraviolet rays.

Examples of the processing method using the processing liquid of the present invention include the following methods.

A. Negative type (1) Overall exposure → image exposure → solvent and 1,3-dialkyl-
Processing with a processing solution containing 2-imidazolidone → development (2) Image exposure → overall exposure → solvent and 1,3-dialkyl-
Processing with processing solution containing 2-imidazolidone → development (3) Overall exposure → image exposure → development and simultaneous use of solvent and 1,3-
Processing with a processing solution containing dialkyl-2-imidazolidone (4) Image exposure → overall exposure → solvent and 1,3-
Treatment with a treatment solution containing dialkyl-2-imidazolidone (5) Overall exposure → image exposure → development → treatment with a treatment solution containing a solvent and 1,3-dialkyl-2-imidazolidone (6) Image exposure → entire exposure → development → Processing with a processing solution containing a solvent and 1,3-dialkyl-2-imidazolidone (7) Image exposure → development → full exposure → Processing with a processing solution containing a solvent and 1,3-dialkyl-2-imidazolidone (8) Image exposure → Development → Solvent and 1,3-dialkyl-2-
Processing with a processing solution containing imidazolidone (9) Image exposure → processing with a solvent and 1,3-dialkyl-2-processing solution containing imidazolidone → development (10) Image exposure → solvent and 1,3-dialkyl-2 simultaneously with development -Processing with a processing solution containing imidazolidone B. Positive type (1) Image exposure → Processing with a solvent and processing solution containing 1,3-dialkyl-2-imidazolidone → Development (2) Image exposure → Simultaneous development with solvent and 1, As a treatment method using a treatment solution containing 3-dialkyl-2-imidazolidone, the plate surface may be uniformly wetted with the treatment solution of the present invention using, for example, a brush or a pad.

The treatment time is not particularly limited, and 1,3-dialkyl-2-
It can be appropriately selected depending on the strength and concentration of the imidazolidone compound and the temperature of the processing solution. However, usually, the effect appears immediately upon contact with the processing solution, and there is no change in the effect even if the treatment is performed for a long time. Usually, it may be about 10 seconds to 15 minutes.

As the developer used in the present invention, those which are usually proposed for a waterless planographic printing plate can be used. For example, water or a mixture of water and the following polar solvent is preferable.

Alcohols (methanol, ethanol, etc.) ethers (dioxane, ethyl cellosolve, methyl cellosolve, butyl cellosolve, methyl carbitol,
(Ethyl carbitol, butyl carbitol, etc.) Esters (ethyl acetate, ethyl cellosolve acetate, methyl cellosolve acetate, carbitol acetate, etc.) Alternatively, development can be carried out directly with the processing solution of the present invention.

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited thereto.

Examples 1 and 2 and Comparative Example 1 The following primer composition was applied to a 0.3 mm-thick aluminum plate (manufactured by Sumitomo Light Metal Co., Ltd.) and heat-treated at 200 ° C. for 2 minutes to provide a 5 μm primer layer.

Polyurethane resin (“SAMPLEN” LQ-T1331, manufactured by Sanyo Chemical Industries, Ltd.) 100 parts by weight Blocked isocyanate (“Takenate” B830, manufactured by Takeda Pharmaceutical Co., Ltd.) 20 parts by weight Epoxy phenol urea resin (SJ9372, Kansai Paint) 8 parts by weight dimethylformamide 725 parts by weight Subsequently, the following photosensitive layer composition was applied using a bar coater, dried in hot air at 110 ° C. for 1 minute, and dried to a thickness of 2 μm.
Was provided.

100 parts by weight of partial ester of naphthoquinone-1,2-diazide-5-sulfonic acid and phenol formaldehyde novolak resin (manufactured by Sumitomo Durez: "Thrillite Resin" PR50622) (degree of esterification by elemental analysis 25%) 4,4 ' -Diphenylmethane diisocyanate 40 parts by weight Dibutyltin diacetate 0.2 parts by weight 4,4'-diethylaminobenzophenone 5 parts by weight P-toluenesulfonic acid 0.8 parts by weight Tetrahydrofuran 800 parts by weight Next, a silicone rubber composition having the following composition on the photosensitive layer After spin coating, the product was cured by wet heat at 115 ° C. and a dew point of 30 ° C. for 3.5 minutes to provide a 2.3 μm silicone rubber layer.

Polydimethylsiloxane (number average molecular weight about 20,000, terminal OH group) 100 parts by weight Vinyl tris (methylethyl ketoxime) silane 8 parts by weight Dibutyltin diacetate 0.1 part by weight γ-aminopropyltrimethoxysilane 0.5 part by weight “ISOPAR” E (Exxon Chemical) 1400 parts by weight Laminated sheet obtained above was laminated with a 10μ thick polypropylene film “Trefane” (manufactured by Toray Industries, Inc.) using a calendar roller, and waterless lithographic printing. I got the original.

A metal halide lamp ("Idol Fin" 2000, manufactured by Iwasaki Electric Co., Ltd.) was used for the printing plate, and a UV meter (Light Measure Type UV402A, manufactured by Oak Manufacturing Co., Ltd.) was used.
The entire surface was exposed for 6 seconds at an illuminance of mw / cm ² .

A negative film having a halftone dot image of 150 lines / inch was vacuum-contacted to the printing original plate obtained as described above, and image exposure was performed for 60 seconds from a distance of 1 m using the above-mentioned metal halide lamp.

Next, peel off the “Trefan” of the exposed plate,
Immerse in a flat vat filled with treatment liquids of various compositions listed in Table 1 at 25 ° C. for 1 minute. After immersion, the processing solution adhering to the plate surface and the back surface is removed with a rubber squeegee, and then a developing solution (water / butyl carbitol / 2-ethylbutyric acid / crystal violet = 70/30/20) is applied to the plate surface and the developing pad.
/0.2 (weight ratio) When lightly rubbed, the silicone rubber layer in the image-exposed portion was removed, exposing the surface of the photosensitive layer. On the other hand, in the portion where only the entire surface was exposed, the silicone rubber layer remained firmly, and an image faithfully reproducing the negative film was obtained.
This printing plate was attached to an offset printing press, and Toyo Ink Co., Ltd. “Toyo King Ultra TKU Aquares G Eye PL”
Was used for printing, and the dot reproducibility was evaluated. Table 1 shows the dot reproducibility.

As is clear from Table 1, Examples 1-2 based on the present invention
Shows good dot reproducibility.

On the other hand, in the processing solution used in Comparative Example 1, the dot reproducibility was remarkably poor, and due to insufficient processing, defects such as spots and scratches occurred in the non-image area (solid white area) of the printed matter.

Example 3, Comparative Example 2 The processing solutions listed in Table 2 were applied to a waterless lithographic automatic developing machine (TWL-1).
160 Toray Co., Ltd.) and 18 liters of water in the pretreatment tank and 40 liters of water in the developing tank. Example 1 The pretreatment liquid temperature was set to 45 ° C, the developing water temperature was set to 25 ° C, and the transport speed was set to 40 cm / min.
The waterless planographic printing plate precursor obtained in the above was subjected to overall exposure and image exposure in the same manner as in Example 1, the exposed plate "Trefane" was peeled off, and the plate was passed through an automatic developing machine to perform development. .
On the 250th, 500th, and 1000th sheets of the Kikuzen plate, the processing solution was sampled, and amine and 1,3-
The concentration of dialkyl-2-imidazolidone was determined, and the dot reproducibility was evaluated in the same manner as in Example 1. Table 2 shows the results.

As is evident from Table 2, in the case of Example 3 based on the present invention, the halftone dot reproducibility did not decrease even when 1,000 copies of the chrysanthemum plate were passed.
In addition, the change in the concentration of 1,3-dialkyl-2-imidazolidone was small, indicating that the treatment solution could be used for a long time.

On the other hand, in the case of Comparative Example 2, good halftone dot reproducibility is exhibited in the 250-sheet version of the chrysanthemum plate, but when 500 copies are passed, the dot reproducibility is reduced. Also, the concentration of monoethanolamine, which is a base component, suddenly decreased, and the base treatment effect was considered to have decreased significantly. As a result, only about 1/3 of the processing liquid of the present invention was used, and the life of the processing liquid was extremely short.

Example 4 A phenol formaldehyde novolak resin having a degree of esterification of 44% was applied to a chemical conversion-treated aluminum plate (manufactured by Sumitomo Light Metal Co., Ltd.) (Sumitomo Duyres Ltd .: "Sumilite Resin" PR50235)
A 3% by weight dioxane solution of naphthoquinone-1,2-diazido-5-sulfonic acid ester (9.7% by weight of an ethanol-soluble component, the degree of esterification is determined from an IR spectrum) was applied, and dried at 60 ° C. for 3 minutes to obtain a thick layer. A photosensitive layer having a thickness of 1.2 μm was obtained. On this photosensitive layer, a 7% "ISOPAR" E solution of a silicone rubber composition having the following composition was added to a 4% by weight of the silicone composition of γ-aminopropyltriethoxysilane (A0800, manufactured by UCC Corporation). Was added and uniformly applied after stirring. After drying, the mixture was cured by heating at 120 ° C. and a dew point of 25 ° C. for 4 minutes to obtain a silicone rubber layer having a thickness of 2.2 μm.

Polydimethylsiloxane (molecular weight about 80,000, both terminal OH groups) 100 parts by weight Ethyltriacetoxysilane 5 parts by weight Dibutyltin diacetate 0.2 parts by weight The waterless lithographic printing plate precursor obtained as described above is used for 150 parts.
A gradation negative film having 2 to 98% of dots per line / inch is vacuum adhered according to a conventional method, and the metal halide lamp used in Example 1 and the UV meter used in Example 1 at a distance of 1 m are used. Image exposure was performed at an illuminance of 11 mw / cm ² for 60 seconds. Except for the negative film
Exposure for 10 seconds (25 mol% of quinonediazide in photosensitive layer
Was photodecomposed to generate a carboxylic acid component).

Next, it is immersed in the treatment liquid of Example 1 for 1 minute at a liquid temperature of 25 ° C. After immersion, remove the treatment liquid adhering to the plate surface and the back surface with a rubber squeegee.
When rubbed with a developing pad containing an 80/20 (weight ratio) developer, halftone dots of 5% to 95% were reproduced, and the silicone rubber layer in the non-image area was not damaged at all. The fixing effect by the 3-dialkyl-2-imidazolidone treatment was sufficient.

[Effects of the Invention] As described above, the waterless lithographic plate-making treatment solution of the present invention comprises 1,
Since it contains 3-dialkyl-2-imidazolidone, the processing effects such as image reproducibility, solvent resistance and developability are extremely excellent, and the effective component in the processing solution such as amine may be reduced. Therefore, the service life of the processing solution is greatly prolonged, and a remarkable practical effect such as a reduction in the number of replacements of the processing solution and a reduction in the amount of use is required.

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-63-155141 (JP, A) JP-A-62-179563 (JP, A) JP-A-58-66940 (JP, A) (58) Field (Int.Cl. ⁶ , DB name) G03F 7 / 32,7 / 00

Claims (1)

(57) [Claims] 1. A waterless lithographic plate-making treatment solution comprising a support and a photosensitive layer and a silicone rubber layer each comprising a substance having a quinonediazide structure as a constituent, the treatment solution comprising a solvent and A waterless lithographic plate-making treatment solution mainly comprising 1,3-dialkyl-2-imidazolidone represented by the formula [I]. (Where R ₁ and R ₂ may be the same or different and may be the same or different alkyl groups having 1 to 10 carbon atoms. R ₃ and R ₄ may be a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, and Or may be different.)